A crossbar array includes a set of upper wires and a set of lower wires. The set of upper wires and lower wires intersect. At each intersection, memory elements are interposed between the upper and lower wires. In some embodiments, each wire in the set of upper wires intersects every wire in the set of lower wires, and vice versa. Consequently, each wire is connected to multiple memory elements. To access a selected memory element at a particular intersection, the correct pair of intersecting wires is selected. Ideally, the memory elements would have nonlinear characteristics which allow the state of a selected memory element to be easily distinguished from other memory elements which are also attached to one of the intersecting wires.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.